Three police officers and a helicopter pilot were killed Tuesday when criminals downed the aircraft in the state of Michoacan in southwestern Mexico, the state governor said in a tweet.
The helicopter was supporting an operation in the Apatzingan region that has difficult land access, tweeted Silvano Aureoles, the governor of Michoacan.
The operation was focused on apprehending leaders of criminal cells, he said.
It was not immediately clear how the helicopter was downed. An officer was injured, Aureoles said.
Michoacan has long been a flash point in Mexico’s drug war, and battles between criminals and security forces occur.
In May 2015, a shootout left 42 gunmen and one federal police officer dead.
In July, the mayor of Pungarabato, a small town in Mexico’s Guerrero state, was killed in a shooting on a highway in Michoacan.